DE2849983A1 - CIRCUIT ARRANGEMENT AND PROCEDURE FOR AUTOMATIC DIFFERENCE BETWEEN SEVERAL STANDARD INFORMATION CONTAINED IN A TIME CODE SIGNAL - Google Patents

Description

Sony Corp. G78P162

DESCRIPTION

The invention is in the field of video tape recorders, and more particularly relates to apparatus as well as a method for reading an encoded time signal and / or an encoded address for precise time and position Determination of a video picture or half picture signal, which is stored on a magnetic tape and used by the Magnetic tape device is read out, for example to be broadcast via a television station. Regarding the genus of the reader for the coded time and / or address signals, reference is made to the preamble of claim 1. The starting point for the underlying method is given in two alternatives in claims 1o and 11, respectively.

Video signals, especially image signals, are becoming whole today recorded predominantly in a track inclined to the tape direction on a magnetic tape, with one such helical track corresponds to the content of a frame or a field. The synchronization to the time and track-accurate assignment of the magnetic head (s) and possibly other drive and guide units within of the tape recorder takes place with the help of a control and monitoring signal, for example on a Adjacent track is recorded in the longitudinal direction of the magnetic tape. Then keys in during playback operation rotating magnetic head, the recorded helical tracks, i.e. the video signal tracks under the control of the from Magnetic tape can also be tapped from the monitoring signal. For example, the distance from one to the next is Helical track in the longitudinal direction of the magnetic tape 0.5 mm and the individual monitoring signals recorded along one edge of the tape follow at a mutual distance of 1mm, i.e. every two inclined tracks is a monitoring signal assigned. The technique of exactly matching the reading magnetic heads to those recorded on the magnetic tape Helical tracks are known in various embodiments and are not the subject of the present invention.

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With this known technique of lane monitoring it is

not possible, a specific single track or, in other words, a specific single image unambiguously to be identified and, for example, in a mixed and to exchange the editing studio for another video image signal. To achieve this it is evident required, the individual helical tracks or at least the helical tracks assigned to a full image the magnetic tape, so for example / two helical tracks address. For this purpose, a special additional signal to be recorded on the magnetic tape can be used. In order to enable an assignment that is accurate in terms of time and position, this additional signal would have to be a time, a Include monitoring and address information.

In fact, there are already norms and standardization proposals in this direction, which the US is based on SMPTE (Society of Motion Picture and Television Engineers) and the European EBU (European Broadcasting Union) agreed for both the NTSC and CCIR standards. It is referred to in this context to the SMPTE Proposals, published in Journal of SMPTE, Volume 79, December 1970, pages 186 to 188 and the book "Videotape Recording -Theory and Practice" by Joseph F. Robinson, New York and London, 2nd edition, 1976, in particular pages 231 to 240 pointed out. According to these proposals recommended to the international standard exist the coded time and address signals - hereinafter referred to as "time code" for short - per field or frame information of 80 bits each recorded on a side track of the magnetic tape, for example on a sound track or a memory track, hereinafter referred to with the internationally customary designation, namely, is designated as the "CUE track". The time code contained in the CUE track can also be nested in the above

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- 10 mentioned surveillance lane.

To the problem underlying the invention To make it clearer, the time code according to the SMPTE standard proposal should first be examined more closely:

This time code contains a time and an address for each frame, so that, based on a fixed point in time, an absolute address or a specific tape position can be clearly located.

Based on a 24-hour cycle of a specified one Tags then the specification for the absolute address of a certain tape position consists of the time specification 8ühr, 32 minutes, 18 seconds. Frame no. 15. For cutting and correction processes, for example, a Desired program change or just for an image exchange this address can be controlled remotely via a electronic computer or from the control panel of a field of view can be entered, for example the following Replace pictures no.16, 17, ..., replace with a multiplication of picture no.15, etc.

With regard to the international time standard, namely the division of a day into two 12 hours no problems. Difficulties for an international program exchange arise, however, from the different Line standards on the one hand and from the different frame rates on the other. So looks - how known - the NTSC standard 525 lines per image and 30 images per second before, while the CCIR or EBü standard has set 625 lines per image and 25 images per second for the majority of European countries. The difference between color television signals according to the NTSC standard or the CCIR standard - based on the mentioned time code - in bit frequency and number of frame signals. According to the international hit

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By agreement, the time code for each frame comprises 80 bits, denoted by the location numbers 0 to 79 are. 32 bits each serve to indicate the time; another 32 bits in places to be explained within the entire time codes are empty and are available to the user of the code, while the remaining 16 bits are available Serve synchronization. In order to be able to guarantee a high level of transmission security and good distinguishability, the code provides a two-phase marking such that the binary digit "1" is represented by a second transition or phase change in the middle of a bit period calculated from the beginning or start time a bit time. The binary digit "O", on the other hand, is present if no transition or phase change can be determined within a bit period.

As already mentioned, there is a difference between the color television signals according to the NTSC standard (SMPTE standard) or. according to the European CCIR standard (EBU standard), among other things in the different frame rates and thus in assignment on the time code in a different bit frequency. In fact, for the NTSC standard, the bit period is

-on OTT "see, while according to the CCIR standard a bit

Period from - ^. 55 " ^{sec he} <? Just would. To be with

To get by with a uniform time code and uniform bit periods, the time code also contains picture numbering, through each image within a time period of 1 see a specific place number is assigned, which accordingly for the NTSC standard from 0 to 29 and for the CCIR standard from 0 to 24 varies. The following table clarifies the assignment of image numbers within the time code:

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NTSC (SMPTE)

CCIR 5 (EBU)

Frame rate 30 frames / sec (525 lines)

25 frames / sec (625 lines)

Image number 0 to 29

0 to 24

When playing back video signals recorded on magnetic tape In particular for television signals, it is now of great importance to know whether the recording is according to the NTSC or according to the CCIR standard. Is the playback device for example Set in a European television studio according to the EBU standard, it can be used for video magnetic tapes cannot play back content recorded according to the NTSC standard unless the device is designed for both standards and a corresponding switchover is made beforehand.

The invention is based on the object of a device for video magnetic tape recorders and / or reproducers to create, with which it is possible to automatically determine according to which standard contained on a given magnetic tape Information has been recorded.

The inventive solution to this problem is short Summary given in claim 1.

The differentiation method on which the invention is based is the subject of claim 9. 30

Advantageous further developments of the inventive concept are characterized in the subclaims.

With the invention it is possible; when playing back video signals that can be tapped from a magnetic carrier medium and from an identification signal, for example

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are wisely accompanied according to the time code explained above, automatically determine the standard according to which the signal was recorded. The test device according to the invention scans the identification signal, i.e. the time code, and delivers a new control signal that is used for the automatic Setting the playback device to the respective recording standard is used.

In particular, the invention thus consists in a time code decoding circuit which is able to determine whether the stored on a present magnetic carrier medium Video signals have been recorded according to the SMPTE or EBU standard. The circuit delivers then to a video tape recorder suitable for both standards (hereinafter VTR device) a setting signal · for setting to the required recording standard.

The invention and advantageous details are set out below explained in more detail with reference to the drawing in an exemplary embodiment. Show it:

1 shows a section in a greatly enlarged illustration from the CUE track of a video magnetic tape for explaining the above-mentioned time code and its Exploitation in connection with the invention; 2 shows the block diagram of an automatic test circuit for differentiating which recording standard is used for a specific signal carrier present was used;

3 to 6 show the time-related representation of signal curves for explaining the mode of operation of the circuit according to FIGS. 2 and
Fig. 7 shows another embodiment for an automatic

Test circuit with features according to the invention. 35

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As already mentioned, each frame comprises - related to the CUE track and corresponding to the SMPTE time monitoring code - 80 time and address bits each, which are basically 64 bits for time coding and for free disposal by the user and 16 bits for one Include synchronization word. The 16 bit synchronization word contains a start time for the picture address, so it defines the start of a picture and on the other hand gives the direction of tape travel. This latter information is necessary because the image address and time information is to be read in both directions of tape travel, both with fast forward (FF) as well as on return (REW), i.e. if the information sequence occurs the other way round.

In Fig. 1, the synchronization word is in the lowest part of the picture shown enlarged. Of the 16 bits each serve the first two bits at the beginning and the end to identify the direction of travel of the tape, with the bit sequence 1 - * 0 the forward direction marked with arrow F or the bit sequence 0 - * 0 marked with Arrow R indicates the direction of travel of the tape in the reverse direction.

In the middle part of Fig. 1, the content of the The relevant image-related 64 bits are shown, which basically contain the image number or the image code, the second code, include the minute code and the hour code. Each of these individual codes is divided into two pieces of information, from where the first relates to the units digit and the second to the tens digit of the respective specification and consists of 4 bits for each decimal place. There is therefore a BCD coding for each individual item. At the chosen Example is the picture no. 29 within the time slot 23 o'clock, 59 minutes, 59 seconds. Like fig.

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can be seen, are located between the one ■ individual digits of the picture code as well as between the individual digits of the hours, minutes and Seconds are "reserve bits" combined into blocks of 4 bits, which are available for free use stand; their total number is 32 bits. With the time and picture number information explained, you can clearly identify a specific video track or a specific image on a video signal carrier exactly.

The structure of this SMPTE time code shown in FIG. 1 is not discussed further at this point; it reference is made to the literature given above.

However, it is important in connection with the invention Slight difference in the number of picture numbers in the SMPTE code on the one hand and in the EBü code on the other. While - as explained above - the picture numbers for the SMPTE code encompass the range from 0 to 29, the picture numbers 0 to 24 apply to the EBü code This slight difference in the time code can be detected automatically, both with fast forward and with rapid or normal reverse operation of a video magnetic tape recorder equipped with the subject matter of the invention. Up to now it has been considered impossible to see the slight difference in the Capture picture numbers with the SMPTE code on the one hand and with the EBU code on the other. With the invention is an accurate one and precise differentiation of the different codes possible within the time of a single frame, however, in practice, to increase security, a decision to set the VTR device to one or another standard only after a few image periods

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for example, is made after 3 image periods.

The basic idea of the invention is based on the fact that the SMPTE code per time slot, so for example per Seconds, 5 frame numbers more, namely the frame numbers 25 to 29, while the EBU code only extends to picture number 24 per time slot. The picture numbering for the two codes looks like this:

SMPTE code: frame numbers 00,01, ... 23,24,25,26,27,28,29 EBU code: Figure numbers 00.01, ... 23.24.

The decision criterion for the two codes consists in checking whether the picture numbers per time slot 25 to 29 are available.

Leaves the CUE track without changing the international time code format and without additional information With the invention, by scanning the picture numbers per time slot, automatically determine after which Standard video signals were recorded.

The embodiment of FIG. 2 shows the block diagram of a time code checking circuit which is able to to distinguish between the SMPTE standard and the EBU standard on the basis of the specified differentiation principle:

At an input terminal 1, a time code signal obtained in a VTR device (not shown) is supplied which is based on a time code reader arrives. The time code reader 2 also determines a signal Pd from the synchronization word, which indicates the direction of tape travel, namely, with reference to FIG. 1, the direction F (forward) or R (backward). That Signal Pd has a high signal level (corresponding to a binary "1") in the case of the forward direction F and sneezes a low signal level (corresponding to a binary "Q") for the reverse direction R.

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The time code reader 2 also supplies a clock pulse signal CP ₁ which is synchronized with the time code and which marks a pulse for each bit of the time code. All time code signals with the exception of the 16-bit synchronization word are stored _{in a memory 3 synchronized by the clock pulse CP 1.} At an output terminal 4 of the memory 3, time and frame number data can be tapped off in parallel form and displayed on a display device (not shown).

In addition, an 8-bit image code signal Sf is picked up via the memory 3 and is applied to the input of image code detectors 5, 6, 7 and 8, respectively. The detector 5 supplies a _{true output signal (binary value "1") designated by S 00} when the image code signal Sf corresponds to the binary value £ oo]. On the other hand, the detectors 6, 7 or respectively emit a _{true output signal (binary value "1") labeled S 24} , S ₂₅ or S ₃₉ when the image code signal Sf corresponds to the binary value | [24], £ 25] or . £ 29].

The image code signal Sf is for the image, for example with the number 20 an eight-digit binary value £ 0010 OOOO] and for the next picture with the number 21 a binary value [0010 0001].

pie detector _{output signals S 34} from detector 6 and S ₃₄ from detector 7 and the directional information related Äusgangssignal Pd from time code reader 2 arrive at AND gates 10 and 11, while further AND gates 9 or at one input each the inverted Pd signal and, at a respective other input, the detector output signals S ₀₀ from detector 5 and Sg from detector 8 are applied. The outputs of the AND gates 9 and 10 are connected to the inputs of an OR gate 13, the output of which is connected to the input of a delay circuit 15 which, under control of the clock pulse CP _{1, increases} the output signal of the OR gate 13 by exactly one bit. Period delayed.

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The two outputs of the AND elements 11 and 12 are connected to the inputs of an OR element 14, the output of which is connected on the one hand to the J input and on the other hand to the K input of a JK flip-flop 17 via an inverter. The J input of this flip-flop is thus acted upon directly by the output signal of the OR element 14, while the inverted signal value is present at the K input. The control input CK of the flip-flop 17 is _{fed by a clock pulse labeled CP 2} , which is supplied by the output of the AND gate 16. Obviously, the clock pulse CP ~ is present when a pulse occurs via the delay line 15 together with the clock pulse CP-.

At the output terminal 18 of the circuit, i.e. at the output of the JK-ITlip-flop 17 occurs the distinguishing signal for SMPTE code or for EBU code; this signal shows a binary "1" for SMPTE code and a binary "0" for EBU code, regardless of the direction of tape travel. With this identification signal at the output 18 can then, for example, via a processor circuit, via a counter or the like a VTR device can be set to the desired standard.

With reference to FIGS. 3 to 6, the operation of the circuit of FIG. 2 will now be described in more detail described:

FIG. 3 initially shows the time-related representation of individual signals identified in more detail in FIG. 2 when reading a code relating to the SMPTE standard in the forward direction of the signal carrier medium. In line A, the clock pulse sequence CP _{1 is} shown, the individual pulses of which follow one another at frame period spacing, ie at a frequency with which the numbers assigned to the individual frames change, thus roughly in the sequence ... [^ 233, C ²⁴ L L ²⁵ I 'Z ²⁶ I' ^{as above he} ~

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The signal Pd shows the binary value "1" in the case of the tape feed, so that the two AND gates 10 and 11 are enabled and the signals S24 and S " _g masked by the detectors 6 and 7 are switched through (cf. Lines B and E in Fig. 3). When the image number 24 occurs, the output of the detector 6 switches to "1" and via the OR gate 13, the signal according to line C in FIG. 3 results at the output of the delay line 15 Clock pulse CP ~ on.

For image number 25, the output of detector 7 switches to "1" (line E in FIG. 3); this binary "1" arrives via the AND gates 11 and 14 to the J input or after Inversion to the K input of the flip-flop 17.

Due to the clock pulse CP ~, the output of the Flip-flops 17 to "1" (see line F in Fig. 3). If the flip-flop 17 is already in the initial state "1" (dashed line in line F), this switching state is retained.

FIG. 4 shows, in a completely analogous manner, the conditions during tape feed in the case of an EBU code; The detector 6 determines the image number 24 and emits the signal S, ^. Since an image with the number 25 does not exist in this case, the output of the detector 7 remains at "0", ie no true output signal S ₂ ^ appears. Because of the clock pulse CP ₂ (cell D in FIG. 4), the flip-flop 17 switches to "0" on the output side or remains in the "0" state (line f in FIG. 4), ie the input-side time code is an EBU code identified.

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28499.

FIGS. 5 and 6 show the conditions during tape return. In the case of the SMPTE code, the sequence of picture numbers occurs in the opposite direction, ie in the sequence ... [02], [Oil], [00], [29], [28], [27] .... and due to of the signal Pd, which is now at level "0", the AND gates 9 and 12 are effective. _{The signal S Q0} (line B in FIG. 5) with level "1" appears at the detector 5 _{when the image number 00 occurs. S Q0} is delayed by one bit period (line 10, FIG. 5). The detector 8 also supplies the signal S ₃₉ when the image number 29 occurs. With the two signals CP ₂ and S ™, the flip-flop 17 at the output switches to signal level "1", which is shown in line F of FIG. 5 or remains at this signal level in the event that this switching state already existed before »

6. With the exception of line E (signal S ₃₉ ), the relationships are analogous to FIG. 5. Since image number 29 is not present in this case, the signal appears at the detector "0" on. Since only the clock pulse CP- is now present, a "0" appears at the output of the flip-flop 17 and thus indicates EBü code (cf. line F in FIG. 6) =

7 shows another embodiment of a test circuit according to the invention in which the frame number code signal Sf arrives at two detectors 5 and 6, through which the signals S _Q0 and S _{24 are} determined and finally the clock pulse via the elements 13, 15 and 16 CP ~ is generated. Obviously, the assemblies 5, 6, 9, 10, 13 and 15 correspond to the assemblies marked with the same references in FIG - Link 21 present. The AND gate 19 is fed, on the one hand, with the output signal Sq ₀ and the signal Pd. The inputs of the AND gate 20, however, are

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fed by the signal S ₃₄ and the inverted Pd signal. The outputs of the AND gates 19 and 20 are connected to the OR gate 21.

In the case of tape advance, the ratios are as explained above with reference to lines A to D of FIG. the clock pulse CP _{3 is} generated. After the occurrence of the picture number 24, however, Sq ₀ becomes "0" or there is no "1" at the output of the OR gate 21. This shows a "0" at output terminal 18 and signals the SMPTE code.

In the case of the EBü code and tape feed, the relationships of lines A to D of FIG. 4 are present, ie the clock pulse CP _{2 is} generated. The detector 5 supplies the signal Sq ₀ = ¹¹ I ", which is sent to the AND element 19. As a result, the flip-flop 17 switches to" 1 "and thus displays the EBU code.

The ratios of the lines apply to the tape return A to D in FIG. 5 (SMPTE code) and lines A to D of FIG. 6 (EBU code). In contrast, for example, to Fig. 2, however shows at the Q output 18 of the flip-flop 17 a "0" for SMPTE code and a "1" for EBU code.

In the two exemplary embodiments of the invention described so far, the delay time at the delay element 15 can also be more than just one bit period, for example 2 or more bits, whichever is earlier Bit position was scanned.

The invention offers the following advantages:

- The test circuit can automatically determine

whether video signals on a recording medium 35

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SMPTE or EBU standards have been recorded.

- The automatic determination and generation of a corresponding identification signal takes place even with rapid Tape forward or rewind.

- The ones developed by SMPTE or taken over by EBü Standard codes for the identifier can be used unchanged; the freely available bits within the time code are not required.

- The invention can be used not only in connection with a special monitoring track, so for example a CUE track, but also in the event that the
Time code storage takes place within the vertical blanking interval.

The testing process according to the invention is not limited to one
limited to a single time slot. To be adequate
To obtain test security, if desired, the
Verification can also be carried out during several time periods, for example during three time slots, in order only then to use the secured result for further processing as a control signal.

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Claims (11)

TER MEER - MCLLER - STEINMEISTER D-80OO Munich 22 D-48OO Bielefeld Triftstrasse 4 Siekerwall 7 Case: S78P162 November 17, 1978 Mü / hm / vL SONY CORPORATION
7-35, Kitashinagawa, 6-chome, Shinagawa-ku, Tokyo / Japan Circuit arrangement and method for automatic differentiation between several standard indications contained in a time code signal. Priority: November 18, 1977, Japan, No. 138 756/77 PATENT CLAIMS 1 _v circuit arrangement for the automatic differentiation between several standard information contained in a time code signal that can be tapped from a recording medium, characterized by - A time code reading circuit (2) which supplies a _{clock signal (CP 1) derived from the repetition frequency of the time code signal;} - An interrogation circuit (5,6,7,8; 5,6) which checks at least part of the information (Sf) contained in the time code signal for the occurrence of certain predetermined values (eg C ⁰⁰ I 'C ²⁴ ]) which are characteristic of the individual standard disclosures and : \ '' .K) 98? 1/0657 Sony Corp. S78P162 - A logical identification and linking arrangement (9-17; 9,10,19,20,21,13, 15-17), which under Control by the clock signal determines whether a from the interrogation circuit when determining the specified The output signal delivered values must be assigned to one or the other standard specification. 2. Circuit arrangement according to claim 1, characterized by a device to check information contained in the time code signal which indicates the direction of movement of the Indicates recording medium relative to a reading station and for generating a directional signal (Pd), which in the Identifying and linking arrangement is fed. 3. Circuit arrangement according to claim 1 or 2, characterized by a Memory (3) which outputs the time code signal delivered in sequential order as a parallel signal. 4. Circuit arrangement according to claim 1, 2 or 3, characterized in that the one standard specification is assigned to an NTSC television signal and another standard specification is assigned to a CCIR television signal is. 5. Circuit arrangement according to claim 4 as part of a for Playback of television signals of different standards set up video tape recorder, thereby characterized in that the output signal emitted by the identification and combination circuit as a control signal for an automatic switchover of the magnetic tape recorder from one to the other television signal form serves. 3098 ^ 1/0657 Sony Corp. S78P162 6. Circuit arrangement according to one of the preceding claims for the automatic differentiation of a time code signal, this is also the case apart from a time information subdivided into time slots of, for example, one second individual, sequentially increasing, regular ones starting from a minimum value (£ θθ3) within the time slot Contains a sequence of numbers that have different lengths for the individual standard information, characterized in that the interrogation circuit to distinguish the standard information in connection with the logical identification and combination arrangement, the minimum value of the sequence of numbers and at least the smaller maximum value within a time slot that is decisive for one of the standards checked. 7. Circuit arrangement according to claim 6 for the automatic differentiation of a time code with two different standard information which differ in terms of the maximum values of the number sequences occurring within a time slot, characterized in that the interrogation circuit (5-8) to distinguish the standard information in connection with the Logical identification and combination arrangement apart from the minimum value (^ 0O]) relevant for both series of numbers, the smaller maximum value (C ²⁴ I) ^{applicable to one standard specification and} the ^{larger maximum value (£ 293) applicable to} the other standard specification of the series of numbers to be distinguished. ^f ^ 09821/0657 Sony Corp. ε73? 162 8. Circuit arrangement according to claim 3, characterized in that - The interrogation circuit contains four detectors (5-8), the input side of which can be tapped from the memory '* (3) Numerical sequence of the image signal numbers is offered, the first detector (5) the minimum value (£ 003) of any sequence of numbers, the second detector (6) the maximum value (^ 24 ^) of the one Standard (EBU) related sequence of numbers, the third detector (7) the first, the maximum value of the a numerical value exceeding standards and the fourth detector (8) a further higher one Numerical value, for example the maximum value of the numerical sequence assigned to the other standard (SMPTE) recorded, - The output of the first detector (5) is connected to a first input of an AND element (9), the inverted direction signal (Pd) is fed to the other input, - The output of the second detector (6) is connected to a first input of a second AND element (10) at the other input of which the direction signal (Pd) is fed, - The output of the third detector (7) is connected to a first input of a third AND element (11) at the other input of which the direction signal (Pd) is fed, - The output of the fourth detector (8) is connected to an input of a fourth AND element (12), the inverted direction signal (Pd) is fed to the other input, - The outputs of the first two AND gates (9 and 10) arrive at a delay circuit (15) which the input signal is delayed by at least one clock period, 909821/0657 Sony Corp. S78P162 5 - - The delayed signal on the one hand and the clock signal (CP ₁ ) supplied by the time code reading circuit (2) on the other hand lead via an AND link (AND element 16) to a clock signal for a flip-flop (17), and that - The outputs of the third and fourth AND element (11 and 12) via an OR link to one Signal input (J or K) of the flip-flop (17) switched are, at the output (18) of which the identification signal for one or the other standard occurs (see Fig. 2). 9. Circuit arrangement according to claim 3 in conjunction with claim 2, characterized in that that - The interrogation circuit contains two detectors (5, 6) to which the sequence of numbers of the image signal numbers that can be tapped from the memory (3) is offered on the input side ) records the maximum value (£ 243) of ^{the sequence of numbers related to the} one standard (EBU), - The output of the first detector (5) with a first input of a first AND element (9) and a first The input of a third AND element (19) is connected, being at a second input of the first AND element (9) the inverted direction signal (Pd) and at one the second input of the third AND element (19) is supplied with the non-inverted direction signal (Pd), - The output of the second detector (6) each with a first input of a second AND element (10) and a fourth AND element (20) is connected, being at a second input of the second AND gate (10) the non-inverted direction signal (Pd) and at a second input of the fourth AND element that inverted direction signal are supplied; 909821/0657 Sony Corp. S78P162 - The outputs of the first and second AND element (9,10) via an OR link to the input a delay circuit (15) arrive which the result under control of the clock signal (CP.,) supplied by the time code reading circuit the OR link delayed by at least one clock period, - The output signal of the delay circuit (15) reaches an input of a fifth AND element (16), at which another input _{is acted upon by the clock signal (CP 1} ) and its output signal (CP ") as a clock signal on the clock input (CK) a flip-flop (17) and that - The output signals of the third and fourth AND element (19, 20) via an OR link to the Signal input (J and / or K) of the flip-flop (17) arrive, at whose output (18) the identification signal occurs for one or the other standard (see. Fig. 7). 10. A method for the automatic differentiation between two in one that can be tapped off from a magnetic tape recording medium Standard information contained in the time code signal, which relates to the NTSC standard or to the CCIR standard for Refer to video signal recording medium in which The coded allocation number for the image signals occurring per second is detected, characterized in that the difference in the number of picture signal allocation numbers determined and then via logical linking steps under control of one of the time code signal derived clock signal an identification signal is generated which has a different signal level for the NTSC standard than for the EBU standard. 909821/0857 11. Procedure for automatic differentiation between two contained in a time code control signal which can be tapped off from a video magnetic tape together with a video image signal Standard information relating to different frame rates in the recorded video image, characterized in that certain picture number codes from the time code control signals read out from the tape is selected and, depending on the selected picture or field code, it is checked whether the time code control signals refers to the first or second timing code. 909821/0657